Although extremely extensive research on tissue regeneration has been carried out worldwide in the last many decades, it appears that to date there are no commercial topical products available to regenerate tissues such as nails and gums. This invention discloses a totally surprising and extremely unexpected discovery that preparations containing an effective amount of a sole active or a principal active ingredient, propylene glycol (PG), a small water-mixable molecule and a known natural metabolite in humans, can be topically applied to promote the growth of or to regenerate vastly different tissues such as nails, gums, hairs and skin.
The use to regenerate gum tissue may be particularly significant. This is because the gum recession, generally being considered as an irreversible aging process, is a common and serious problem especially in elderly adults. It may result in loosening and loss of teeth and negatively affect the quality of life. Treatments with dental implant or use of artificial teeth are expensive. Although some herbal products purportedly claimed to be useful for helping grow gums are available, there is an urgent need to find a simple, safe, effective method to regenerate gum tissue or to slow down gum recession.
The exact reason for these astonishing findings is unknown and their potential mechanisms are, undoubtedly extremely complicated especially at molecular levels (B. Galliot et al., Development, 144:357-364, 2017 and references therein). However, this may be simply speculated to be directly or indirectly attributed to rejuvenation of their tissue stem/progenitor cells. See W. L. Chiou, Scient Pages Dermatol. 1: 1-5, 2017 and references therein.
PG is often used as a solvent in cosmetics and drugs. PG could treat acne in humans (W. L. Chiou, U.S. Pat. No. 8,846,646, 2014), and could even serve as a universal microbicide to treat a wide variety of other topical infections (W. L. Chiou, U.S. Pat. No. 8,513,225, 2013).
To date, PG is still commonly and mistakenly regarded as a highly undesirable ingredient in skincare products (W. L. Chiou, U.S. Pat. No. 8,513,225, 2013). It is, in fact, a very safe compound when used properly. For example, rats fed with water containing 10% of PG and dogs fed with food containing 8% of PG for two years have been shown to cause no adverse effects. It is generally regarded as safe (GRAS).